Goal: Compute biomass estimates from fish length
Data conversion
We have several main cases:
- We have the total length (TL):
- We have the right unit for a and b: g and cm => done
- We have the wrong units for a and b => need to transform using formulas
- We have another type of length:
- We need to first transform the length into the total one using the formula in column "LL_Equation_for_WL"
Main formula: W = a * L^b
Unit transformation (source: Fishbase)
a'(cm, g) = a (mm, g)*10^b
a'(cm, g) = a (cm, kg)*1000
a'(cm, g) = a (mm, mg)*10^b/1000
a'(cm, g) = a (mm, kg)10^b1000
Relationship reference: https://www.fishbase.de/manual/fishbasethe_length_weight_table.htm
code: https://github.com/NCEAS/ca-mpa/blob/main/analyses/1performance_eco/code/biomass_reference_file_prep.R
Goal: Compute biomass estimates from fish length
Data conversion
We have several main cases:
Main formula:
W = a * L^bUnit transformation (source: Fishbase)
a'(cm, g) = a (mm, g)*10^b
a'(cm, g) = a (cm, kg)*1000
a'(cm, g) = a (mm, mg)*10^b/1000
a'(cm, g) = a (mm, kg)10^b1000
Relationship reference: https://www.fishbase.de/manual/fishbasethe_length_weight_table.htm
code: https://github.com/NCEAS/ca-mpa/blob/main/analyses/1performance_eco/code/biomass_reference_file_prep.R